The genus Mapouria was named by Aublet for plants from French Guiana. These plants have now been shown with morphological (Taylor, 1996) and molecular (Andersson, 2002; Razafimandimbison et al., 2014) data to belong Psychotria L., and within this to a Neotropical clade that is called, in Neotropical floras, Psychotria subg. Psychotria. Psychotria is a large and complex group, and currently is circumscribed as its own tribe or subtribe. Mapouria has been known to be a synonym of Psychotria since the 1880's. Bremekamp reviewed the Psychotrieae (s. lat.) and related genera in both the Guianas and Madagascar using a somewhat different set of characters than previous authors had used, in particular some features of the pyrenes, and constructed a different classification than most previous authors used. As with most taxonomic studies of the Psychotrieae, several of his conclusions are supported by molecular data but others are not. Bremekamp separated Mapouria based on its endosperm being ruminate on at least one side, vs. not ruminate in Psychotria; in this circumscription, Mapouria included species from the Neotropical, Africa, Madagascar, and southern Asia, and has Grumilea Gaertn. as a synonym. He noted in his study of the Psychotrieae in Madagascar (Bremekamp, 1963) that apparently Psychotria and Mapouria are synonyms, but stated that the type of Psychotria was heterogeneous and that he would use these as separate names until that lectotypification was resolved. Psychotria is today circumscribed more broadly to include species with both entire and ruminate endosperm, and the Madagascan species described in Mapouria have been transferred to Psychotria (Davis et al., 2007; Davis & Govaerts, 2008).
Bremekamp's classification has never been widely accepted. Contemporaneously with Bremekamp's work in fact, Petit (1964) was finishing a monograph of the African species of Psychotria, in which he discussed the two type elements of Psychotria (Petit, 1964: 11-12) and expressed his preference for the Jamaican specimen, which would make Mapouria synonymous with Psychotria. In this work Petit considered Grumilea in some details and synonymized it with Psychotria. Subsequent Neotropical authors have circumscribed Psychotria subg. Psychotria (Steyermark, 1972) or Psychotria s. str. (Andersson, 2002) similarly to Petit, and have considered Mapouria a synonym of this group. Subsequent Paleotropical suthors have also included Grumilea within Psychotria (Verdcourt, 1976; Davis et al., 2007; Flora of China, publ. 2011; Lachenaud, pers. comm.).